that's where emily schmidt joins us now, live, with a preview. and, emily, tea party candidates are getting a lot of attention today. >> reporter: this is the focus on them today. rob and vinita, good morning to you. republicans hoping to unseat democrats in november. but today, and first, tea party candidates are hoping to oust some of the gop favorites. the biggest stage for a potential upset today is in delaware. >> how are you doing? >> reporter: on this primary day in seven states, some candidates worry this may not be the year to be a party favorite. >> i actually have a conservative voting record, as far as finances are concerned, in congress. and while i'm a moderate, that's generally on the social issues. >> reporter: in democrat-dominated delaware, gop leaders think eight-term congressman mike castle is their only hope to win vice president biden's old senate seat. instead, castle is in a fight race with christine o'donnell. she has ran before. but this time, she has tea party backing. >> republicans are backing away. they get behind ca